Termites ensure a similarly successful outcome using chemical signals called pheromones. As the nest-builders chew soil pellets into a cement-like paste, their saliva adds a chemical which, for just a few minutes, can be “smelled” by other builders over a distance of a centimetre or so. This sets up a positive feedback: the more a pillar is augmented, the stronger a pheromone source it becomes, causing the termites to add even more material.
via newscientist.com